In an exclusive interview with the Eastern Daily Press, Ms Spelman argued that she precisely followed official guidelines in reaching her decision to grant £91m worth of financing to fund the incinerator on the outskirts of King’s Lynn.

In November last year the cabinet minister wrote to Norfolk County Council leader Derrick Murphy raising concerns about the high level of public opposition to the incinerator plan, but after further correspondence approved funding for the scheme in January.

Asked if she accepted that a U-turn had taken place she said: “Not at all. My test is one of broad consensus, that’s the criteria I look for.

“I asked [Norfolk county council] for evidence of broad consensus, and that doesn’t mean everybody, and they produced the evidence for me for the support from the district councils for their waste strategy. That’s what I required and that’s what they provided me with.”

Some 65,000 members of the public voted against the siting of the incinerator in a poll, meanwhile West Norfolk Council and some of the county’s MPs have pitched themselves against the plant too.

But Ms Spelman said siting of the incinerator was a planning issue which had nothing to do with her finance decision.

To approve funding she only needed to ensure there was “broad consensus” for the county council’s overarching waste management strategy, she said; regardless of opposition to the location of any specific infrastructure.

From that point of view, she went on to suggest, no amount of public anger about the Saddlebow site of the incinerator would have made any difference to her decision.

But in an apparent rift between two Conservative members of the government, the environment secretary was immediately criticised by fellow Tory minister and North West Norfolk MP Henry Bellingham who suggested she had taken a “narrow” view of guidelines.